Hi, this is my first post. I have a 1986 420 sel with 100 000 km on it. Recently it has developed a problem with stalling. By following old posts I have been able to trouble shoot it quite a bit and narrow things down. I have replace the fuel pump relay and the fuel filter but am still experiencing the same problems. What I have discovered is both fuel pumps work, but once the engine warms up the fuel pump relay will turn off shutting down the power to the pumps. The car will restart but the relay will turn off again only alot quicker (which I believe is because the engine is now warm). What would cause the fuel pump relay to turn off? Can any other sensors or relays cause it to do this? Thanks, I hope someone can help.